Paris St-Germain came from a goal down to overcome ten-man Saint-Etienne and extend their lead at the top of Ligue 1 to 14 points.
Denis Bouanga handed St Etienne a 23rd-minute lead after Neymar's early effort was ruled out for offside.
Bouanga's opener, which was confirmed by VAR after he was initially flagged offside, was the 11th time Mauricio Pochettino's PSG have conceded the first goal the league in 2021, their most in a single calendar year since 2012.
Marquinhos headed PSG equalizer from the resultant free-kick before half-time after Timothee Kolodziejczak was given his marching orders for a tackle on Kylian Mbappe.
With 11 minutes left on the clock, Angel di Maria curled in a goal, and Marquinhos added a third for the visitors in stoppage time.
Despite Sergio Ramos, a former Real Madrid defender, making his first appearance for the club since joining in July, the result was flattering.
Lionel Messi, who assisted all three goals for his team, missed a golden opportunity to put the visitors ahead midway through the second half when he went wide after Neymar's attempt was stopped.
But he made good, setting up Di Maria with a brilliant outside-of-the-foot pass before crossing for Marquinhos as PSG extended their lead after second-placed Nice lost 1-0 to Metz on Saturday.
